Dr. Rusdorf, in his work on the influence of European climate, regards the temperate zone as the brain-making region, and attempts to prove it by physiological deductions. The brain of the Caucasian, he says, determines the superiority over the other races, and it is the standard of the organism. This, he maintains, is produced by the richness of albumen in the blood, which is also dependent upon the oxygen of pure air. The extensive observations of the English Registrar-General show indisputably that the elevation of the soil exercises as decided an influence on the English race as it does on the native races of other climes and soils. They also show that the finest animals are raised in the healthiest districts. We see that certain heights above the plains are remarkably exempt from maladies which devastate nations inhabiting lower levels. Cholera, remittent fever, yellow fever, and plague, disappear at well-defined degrees of elevation. At Vera Cruz, and along its latitude, the yellow fever vanishes at the height of three thousand feet above the Gulf shores. The Prussian, in his "Medicinische Geographie," appears to indicate with great degree of certainty the limits and altitudes of the three zones, into which he classifies the catarrhal, the dysenteric, and the scrofulous diseases. The scrofulous zone ceases at an altitude of two thousand feet above the level of the sea, and here, he says, there is no pulmonary consumption, scrofula, cancer, or typhus fever. "It is," says Babinet, "the climate of each country which permits or arrests the development of the human race, which, joined with the industry of populations, imposes limits to the numerical force of each meteorological district, and which subsists four million of men in fertile Belgium, which is no more than a small fraction of the territory of France, whilst Siberia can with difficulty nourish a part of that number with an extent which is twenty-six times that of France." "All over the world, physical circumstances," exclaims Draper, "control the human race." XIX. It is vain to assert that the atmospheres of the maritime or the low levels do not affect the physical and mental condition of men; and after all, Fontenelle was right when he maintained, in a curious paradox, that inspiration is a barometer that varies, which mounts to genius or descends to absurdity, according to the inconstancy of the weather; that there are unhealthy countries, full of mists, winds, tempests, that never produce clear understandings; and, on the contrary, there are lands with beautiful skies and fields filled with sunlight and roses which give out flashes of divine light.